[Gr. ἀπαγωγή leading away, abduction, also used by Aristotle in the logical sense, f. ἀπ-άγειν to lead off.]
† 1. Logic. The species of syllogism, or syllogistic reasoning, called ABDUCTION. Obs.
1727–51. Chambers, Cycl., Abduction in logic, a kind of argumentation by the Greeks called Apagoge.
1872. Grote, Aristotle, I. vi. 290. Another variety of ratiocinative procedure, which he calls Apagoge or Abduction.
2. A demonstration that does not prove a thing directly, but shows the absurdity or impossibility of denying it; a reductio ad absurdum.
a. 1753. Berkeley is cited in Worcester.
† 3. Math. ‘A progress or passage from one proposition to another; when the first having been once demonstrated, is afterwards employed to the proving of others.’ Chambers, Cycl. Supp., 1753. Obs.
